Boiler-alarm.



PATENTED DEC. 22, 1903.

W. s. G. HARRIS.- BOILER ALARM.

APPLICATION FILED APR. 7. 1903.

2 SHEETS- SHEET 1.

H0 MODEL.

W ifgesszs No. 747,420. 7 PATENTED DEC; 22, 1903. W. S. G, HARRIS.BOILER ALARM.

APPLICATION FILED APR. 7. 1903. no MODEL. I 2 SHEETS-SHEET 2.

15 M Riga- 2.

/ l I I o Jhforgzys UNITED STATES.

- Patented December 22, 1903.

PATENT OFFICE.

WARNER S G. HARRIS, OF SAN LUIS OBISPO, CALIFORNIA, ASSIGNOR OF ONE-HALFTO JAMES LEAVITT, OF SAN LUIS OBISPO, CALIFORNIA.

BOILER-ALARM.

SPECIFICATION forming part of Letters Patent No. 747,420, dated December22, 1903- Application filed April 7, 1903. Serial No l494. (No model.)

- To all whom it may concern:

Be it known that I, WARNER S. G. HARRIS, a citizen of the United States,residing at San Luis Obispo, in the county of San Luis Obispo and Stateof California, have invented a new and useful Boiler-Alarm, of which thefollowing is a specification. I

This invention relates to boiler-alarms,and is especially directed tothat class of devices which are designed for audibly indicating thefalling of the water in the boiler to a low-water or danger point, andhas for its objects toproduce a device of this character ofcomparatively simple construction, one which in practice willefficiently perform its functions and will obviate the liability ofprematurely signaling or of failure to operate, or, in other words, adevice which will positively sound the alarm when the water arrives atthe danger-point, but which cannot operate until such point is reached.

To these ends the invention comprises the novel details of constructionand combination of parts more fully hereinafter described and claimed.

In the accompanying drawings, Figure 1 is a sectional elevation of aportion of a boiler, illustrating the invention applied thereto. Fig. 2is a similar view showing the position of the parts when released forsounding the alarm. Fig. 3 illustrates a similar modified form of thedevice. Fig. 4 is a detail view of the plunger-rod and the parts whichare con nected with and movable thereby. Fig. 5 is a similar view of theinner tube which forms a seat for the lower end of the actuatingspring.

Referring tothe drawings, 1 indicates the crown-plate of a boiler, and 2the crown-sheet of the furnace. These parts may be of the usual or anydesired construction, inasmuch as they form no part of thepresentinvention.

3 indicates a plug which is tapped through the crown-sheet of thefurnace and projects a suitable distance above the same and has tappedcentrally into its upper face the lower threaded end of vertical. tube4, which constitutes the main outer protecting-casing of the presentdevice. The tube 4 passes upwardly through a plug 5,tapped into theboilercrown, and a packing member 6, tapped at its lower end into theplug. Mounted on the upper end of the tube 4 is a movable cap 7, whichhas centrally secured to its upper face a vertical valve-rod 8, whichcarries between its ends a valve 9, slidingly mounted in a casing 10,the rod 8 being extended through the valve-casing and provided at itsupper end with a suitable spring 11, which tends normally-to force therod downwardly and main- 6o tain the cap 7securely-seated upon the upperend of the tube 4 and further maintains the valve 9 in its normallyclosed condition.

12 indicates a steam-pipe connected at its lower end to theboiler-crownand at its upper end to thevalve-casing 10. This pipe is infree communication with both the boiler and the valve-casing and isadapted for communication with a whistle 13, attached to the casing 10for communication therewith. The valve 9 7o normally closescommunication betweenthe pipe 12 and the whistle, but is adapted foroperation in a manner, presently to be described, to establishcommunication between the pipe and whistle in order that the latter maybe sounded through the medium ofsteam conducted to the same by theformer. The upper end of the rod 8 is movably sustainedby a suitableguide 14:, formed in the crownblock 15 of a casing 16, sustained by thesteam-pipe 12 and adapted toprotect thevalvecasing,valve-spring,andadjacent mechanism from dust and other foreign matter:

Mounted within the tube 4 is a second tube 17- of a height equal toabout one-half of the tube' l and provided at its upper open end with anannular outwardly-extending flange 18. The lower end of this tube restsupon the upper face of the block 3. I

19 indicates a plunger-rod which extends through the tube 17 and isattached at its lower end by solder or other readily-fusible metal 20 tothe outer face of the plug. This rod is of a length equal to the lengthof the tube 4 and bears at its upper end centrally 5 upon the removablecap 7. Mounted on the rod 19 at a suitable point below its upper end isa disk-like head 21, and between the head 21 and the flange 18 of thetube 17 is a spring 22, which is coiled around the rod-andbears at itsends against the flange 18 and head 21, respectively. The normaltendency of this spring is to force the rod 19 upward, which movement ofthe rod is prevented, owing to its being attached at its lower end tothe plug 3, as before stated.

The plug 3 has its lower face cored out or channeled at a point beneaththe tube 4, as indicated at 23, thus reducing the thickness of the plugat this point.

In operation, supposing the parts to be in the position illustrated inFig. 1, with the rod 19 attached to the plug 3, and that the water inthe boiler falls to the low-water or danger point, which is on a linewith the upper face of the plug, the heat from the furnace will bequickly communicated to the plugand fuse the solder or like metal 20,thus detaching the lower end of the rod 19 from the plug andpermittingthe spring 22 to force the samebodily upward. As the rod movesupward it in turn forces the cap 7 upward from the end of the tube 4 andmoves rod 8 to open the valve 9 and permit the steam to flow from pipe12 to the whistle 13 and sounding the same. In this connection it is tobe noted that, owing to the coring out of the plug, as at 23, thethickness of the same beneath the tube 4 is reduced, which permits theheat from the fnrn ace to act more rapidly in fusing the metal 20.

In the modification shown in Fig. 3 the plug 3 has formed on its outerface a reduced neck 24, which carries at its outer end a platform 25,which receives and sustains the lower ends of tubes 4 17 and rod 19,which latter is attached by fusible metal 20 to the upper face of theplatform. This construction is intended for use when the device isattached to boilers whose furnaces are unusually hot and will, asreadily understood, permit the water in the boiler to fiow beneath theplatform 25, and thus prevent premature fusing of the metal 20, or, inother words, will prevent fusing of the metal until the water falls tothe proper point below the platform.

From the foregoing description it will be seen that I produce a simpleand efficient device which in practice will be positive in its operationand will be absolutely free from liability of improper action, and inattaining these ends it is to be understood that I do not limit orconfine myself to the details herein shown and described, inasmuch asvarious minor changes may be made therein without departing from thespirit or scope of the invention.

Having thus described the invention, what I claim is- I 1. In a deviceof the class described, the combination with a boiler and its furnace,of an alarm, means for sustaining the same, a conduit for conductingsteam from the boiler to the alarm, a valve, means for maintaining thevalve normally closed, said means including a member attached to thefurnace crownsheet by a fusible metal, and means operated by the releaseof the member for automatically opening the valve.

2. In a device of the class described, the combination with a boiler andits furnace, of

an alarm, means for sustaining the same, a

conduit for conducting steam from the boiler to the alarm, a valve,means for maintaining the valve normally closed, a casing, a rod mountedin the casing and having its lower end attached to the furnacecrown-sheet by a fusible metal, and a spring for actuating the rod whenreleased from the crown-sheet to automatically open the valve.

3. In a device of the class described, the

combination with a boiler and its furnace, of

an alarm, means for sustaining the same, a conduit for conducting steamfrom the boiler to the alarm, 21 valve, means for maintaining the valvenormally closed, a tubular casing connected at its lower end with thecrownsheet and extending through the wall of the boiler, an inner tubemounted in the casing and provided at its upper end with a flange, a rodextending through the inner tube and having its lower end associatedwith the go crown-sheet bya readily-fusible metal, ahead carried by therod, a spring mounted on the rod between the flanged end of the innertube and the head, said spring tending to force the rod upward, andmeans actuated by the upward movement of the rod, when released from thecrown-sheet, to open the valve.

4. In a device of the class described, the combination with a boiler andits furnace, of an alarm, means for sustaining the same, a conduit forconducting steam from the boiler to the alarm, a valve for controllingthe admission of steam to the alarm, a tubular casing connected at itslower end with the crownsheet and extending through the wall of theboiler, a cap movably mounted on the outer end of the casing, arodcarried by the cap and connected with the valve,a spring acting upon therod to maintain the valve normally closed, a rod mounted in the casingand associated at its lower end with the crown-sheet by means of areadily-fusible metal, and a spring adapted to force the rod upward whenreleased from the crown-sheet to cause the same to actuate the valve-rodto open the valve.

In testimony that I claim the foregoing as my own I have hereto aflixedmy signature in the presence of two witnesses.

WARNER S. G. HARRIS.

Witnesses:

P. A. H. ARATA, J OHN SMITHERS.

